A magnetic energy wave device has a winding spiral pipe, a magnetic conductive metal layer, a hollow coil holder, and a circuit board. A magnetic switch is assembled at a water inlet of the winding spiral pipe. The magnetic conductive metal layer is sleeved outside the winding spiral pipe. The winding spiral pipe and the magnetic conductive metal layer are assembled in the hollow coil holder. A coil is wound around the hollow coil holder. The circuit board is connected to an external power source, and is electrically connected to the magnetic switch and the coil. When water passes through the water inlet, the magnetic switch connects the power source and the coil. The coil and the magnetic conductive metal layer therefore produce dynamic magnetic fields to magnetize fully water in the pipe.